For centuries, scientists, engineers and technicians have used optical systems of varying complexity to assist in research, analysis, diagnosis, repair and other tasks. In particular, the microscope—generally an optical system for obtaining an enlarged view of a subject—is a mundane but indispensable tool.
Microscope users often experience a common frustration: that of locating a particular feature of a subject that is visible without magnification, but hard to find in a magnified view (or vice versa). One common solution is to provide a range of magnifications in the microscope. The desired area to examine is located and centered in the field of view under a low magnification, then progressively higher magnification objectives are swapped in until the necessary enlargement is reached. Although effective, this approach wastes time with objective-swapping and (often) re-focusing or re-centering, and if the operator disturbs the subject while adjusting the magnification, the process must be restarted. Furthermore, when the desired final magnification is not much greater than the “spotting” magnification, the method may provide only modest time savings over simply searching for the desired feature under the final magnification objective.
Alternate methods of spotting, targeting or positioning a subject on a microscope that permit rapid, direct-vision alignment to place a target location within the microscope's enlarged field of view may be of significant value.